The purpose of this study is to develop and pilot test a culturally relevant, theory-driven adaptation of the evidence-based intervention Project START to improve post-incarceration health care engagement among transgender ('trans') women. The adapted intervention (Trans START) will focus on improving linkage to and engagement in four health care domains (HIV, substance use, mental health, and transgender-related medical care), responsive to each participant's self-identified needs. Incarceration is a significant publi health issue that disproportionately impacts trans women, and the cycle of incarceration interacts with high levels of substance use, mental illness, and HIV to produce an elevated burden of disease among trans women. Trans women who have been arrested are more likely to report mental illness, using substances, engaging in risky sex, and needing trans-sensitive services upon release. Gender differences in health, post-release service needs, and predictors of engagement in healthcare call for gender-specific strategies. This adaptation of Project START will incorporate an innovative, transgender-specific theoretical model, the Model of Gender Affirmation. Unmet need for gender affirmation predicts HIV risk among HIV- trans women and treatment failure among those who are living with HIV, and access to gender affirmation is related to better mental health. Furthermore, access to gender affirmation supports linkage, engagement, and retention in care among trans women who are living with HIV. Using the ADAPT-ITT strategy to guide the adaptation process, we will conduct qualitative interviews with 15-20 trans women who are incarcerated in the San Francisco County Jail (SFCJ), prior to and after release. We will also conduct qualitative interviews with 5-10 key stakeholders who work with this population in SFCJ and in the community. Once the adapted materials are finalized, we will conduct a pilot randomized controlled trial to test the feasibility and acceptability of the adapted intervention, as well as the protocols and procedures, to inform a future full-scale randomized controlled trial for efficacy of the adapted intervention. To accomplish this aim, we will randomize 50 trans women who have been incarcerated for a minimum of one week to either Trans START (adapted Project START curriculum plus treatment as usual) or treatment as usual alone (TAU). We expect that following intervention exposure, relative to control group, Trans START participants will report higher rates of HIV testing (among HIV- women at baseline) and higher HIV medical appointment attendance (for HIV-positive trans women). Moreover, intervention participants will report: a) higher levels of linkage to and engagement in substance abuse treatment, mental health care, and transgender-related medical care (among participants who identify these as needs). With the data from the feasibility and acceptability pilot, we will leverage funding to conduct a larger efficacy study of the adapted curriculum with the goal of producing a replicable, culturally relevant, evidence-based health promotion intervention for incarcerated trans women who are preparing for release into the community.